To Next PageTo Next PageWhat does it mean if my Vaillant ecoTEC plus 612 Boiler shows eBUS undervoltage?
An eBUS undervoltage indication means there could be a short circuit on the eBUS, an overload on the eBUS, or two power sources on the eBUS with different polarity. Check the eBUS connections and power sources.
What to do if the heating system of my Vaillant ecoTEC plus 612 Boiler is not full of water?
If your Vaillant Boiler's heating system isn't full of water or charged correctly, make sure the heating system is full of water and charged to between 1 and 1.5 bar. If it's not, refill and vent the system.
What to do if my Vaillant Boiler is dry firing?
If your Vaillant Boiler is dry firing, it indicates there may be too little water in the appliance, a defective water shortage switch, a defective cable to the pump or water shortage switch, a blocked or defective pump, or the pump output is too low. Ensure adequate water supply and check the water shortage switch and pump.
Why does the flame go off during operation in my Vaillant ecoTEC plus 612 Boiler?
If the flame goes off during operation and subsequent ignition attempts fail in your Vaillant Boiler, it could be due to a temporarily stopped gas supply, spark failure in the ignition transformer, or faulty earthing of the appliance. Check gas supply and ignition system for faults.
What to do if my Vaillant ecoTEC plus 612 Boiler shows a gas valve shutoff delay?
If your Vaillant Boiler shows a gas valve shutoff delay, the gas valve may be leaking, or the electronics may be defective. Inspect the gas valve for leaks and test the electronics.
What causes a short circuit in the tank sensor of my Vaillant ecoTEC plus 612 Boiler?
A short circuit in the tank sensor of your Vaillant Boiler can be caused by a defective NTC, an earth leak/short circuit in the cable loom, or a damp plug connection. Inspect and replace the NTC or repair damp connections.
What does it mean 'No valid DSN in AI and/or BMU' in Vaillant ecoTEC plus 612?
If your Vaillant Boiler displays 'No valid DSN in AI and/or BMU', it indicates a spare part failure where the AI and motherboard were interchanged at the same time. Replace faulty components to resolve DSN issue.
What to do if the water pressure sensor or cable harness hydraulics are defective in my Vaillant ecoTEC plus 612?
If the water pressure sensor or cable harness hydraulics are defective in your Vaillant Boiler, it could be due to a broken line to the water pressure sensor, a short-circuit at 0 V, or a defective water pressure sensor. Inspect and replace the water pressure sensor or repair the line.
What to do if there is a short circuit in the flow-NTC of my Vaillant Boiler?
If there is a short circuit in the flow-NTC of your Vaillant Boiler, it could be due to the NTC plug shorted to the casing or a defective NTC. Inspect and replace the NTC if defective.
Why is there a short circuit in the return-NTC of my Vaillant ecoTEC plus 612 Boiler?
A short circuit in the return-NTC of your Vaillant Boiler is often due to a defective NTC. Inspect and replace the NTC if defective.
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